Treating industrial wastewater – with soy

Soybean hulls are primarily a by-product of processing or oil extraction. Traditionally, they are used as a fibre supplement in animal feed as way of creating some value-added use for them. But research at the University of Windsor focuses on a new and environmentally friendly use for these seed coats as well – in industrial wastewater treatment.
Keith Taylor, a professor in the Department of Chemistry and Biochemistry, and colleagues are studying how soybean peroxidase can be used to clean waste water, especially from refineries, metal casting industries, wood products production and coal tar processing.

The peroxidase is extracted from the soybean hulls and the enzyme is used to oxidize phenolic compounds in the waste water. This means the enzyme actually builds up the phenolic compounds in the water to the point where they become insoluble and can be physically separated from the water.

The clean water can then be safely re-used. Once the peroxidase has been removed from the hulls, they can still be used in animal feed without any impact on the quality of the feed.

Research by others has also shown that different soybean varieties have different levels of peroxidase present in their seed coats. This provides an excellent opportunity for developing an identity-preserved, value-added market based on peroxidase.

Currently, there are no providers of the enzyme on a commercial level in Canada, or elsewhere. Taylor is working on encouraging supply chain partners to join together to develop a commercial enzyme extractor to provide a product that could be used for wastewater treatment around the world.

Once this is in place, Taylor believes that it could be used to extract other natural materials from soybean hulls as well, such as peptides, which have been shown to be an effective cancer treatment.

A group of researchers from the University of Ottawa and Agriculture and Agri-Food Canada in Ottawa and London are currently investigating the possibility of the seed coat as a production system. This means getting the hull to re-produce a protein whose gene is manually inserted into it to create a source for medications or certain antibodies.

Taylor says this has been dubbed molecular pharming. He suggests that commercialization of soybean peroxidase, using one industry’s by-product to treat the waste of another’s, represents a whole new level of assistance for the transition from a petroleum-based economy to a bioeconomy.